Q. Explain Spoilage of pasteurized milk?

You would recall that pasteurization is one of the techniques to control and destroy the pathogenic, as well as, .spoilage bacteria in milk and milk products. There are certain bacteria which can withstand pasteurization temperatures. They are 'thermoduric bacteria' which are heat-resistant. Streptococcus thermophilis, Streptococcus faecalis, Cornyebacterium lacticum and Micrococcus luteus are some of the commonly found thermodurics. The spores of 3. cereus are also found in pasteurized milk and they are also responsible for spoilage when held at normal temperatures. The spore formers especially Bacillus subtilis are responsible for the spoilage of Ultra High Temperature (UHT) processed milk. But generally the spoilage also results due to the enzyme activities.